# GrowthBook vs PostHog

> GrowthBook scores 70.1 (BB) on agent readiness against PostHog's 68.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth and transparency & trust. Both do analytics experiments. Category scores, facts, verdicts and agent notes…

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- Updated: 2026-10-09

GrowthBook scores 70.1 (BB) on agent readiness against PostHog's 68.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth and transparency & trust. Both do analytics experiments.

- GrowthBook: grade BB, 70.1/100, rank #155 of 842. Markdown https://www.anchorterminal.com/tools/growthbook.md · JSON https://www.anchorterminal.com/api/v1/tools/growthbook.json
- PostHog: grade B, 68.4/100, rank #204 of 842. Markdown https://www.anchorterminal.com/tools/posthog.md · JSON https://www.anchorterminal.com/api/v1/tools/posthog.json

## Which one, for what

### GrowthBook (BB)

Good for: Teams that want flags and experiments analysed against their own warehouse, with an open-source core and a self-hosted option.

Ahead on:
- Reliability, 86 against 74

Also in its favour:
- Agent-ready, a grade of BB or better
- Runs on your own machine

Watch for: The API tools take a path and a JSON string and don't validate payloads, so correct calls depend on the bundled skills

### PostHog (B)

Good for: An agent that answers product questions in SQL or with funnel, retention and trends queries, and that manages feature flags, experiments and error tracking in the same project.

Ahead on:
- Schema & documentation, 81 against 76
- Security & auth, 84 against 68
- Transparency & trust, 83 against 74

Watch for: 31 incidents on the status page between 9 July and 6 October 2026, four of them analytics query timeouts or failures


## Score by category

| Category | Weight | GrowthBook | PostHog | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 86 | 74 | GrowthBook +12 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 76 | 81 | PostHog +5 |
| Agent ergonomics | 13% (16.2 this run) | 76 | 78 | PostHog +2 |
| Security & auth | 14% (17.5 this run) | 68 | 84 | PostHog +16 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 89 | 89 | even |
| Transparency & trust | 7% (8.8 this run) | 74 | 83 | PostHog +9 |
| Negative events | ≤15 | -3 | -7 | |
| **Total** | | **70.1 · BB** | **68.4 · B** | |

## Facts side by side

| Fact | GrowthBook | PostHog |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | GrowthBook, Inc. | PostHog Inc. |
| Hosted endpoint | `https://mcp.growthbook.io/mcp` | `https://us.posthog.com` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | MIT for the core and for the MCP server. Three enterprise directories in the main repository are under GrowthBook's enterprise licence. GrowthBook Cloud is a hosted service under the Customer Agreement | MIT for the repository outside the `ee` directory, which has its own licence. PostHog Cloud is a hosted service under PostHog's terms |
| Tools exposed | 4 | 1096 |
| Read-only variant documented | no | yes |
| llms.txt | yes | yes |
| MCP registry | `io.github.growthbook/growthbook-mcp` | `io.github.PostHog/mcp` |
| Last release | 2026-10-06 | 2026-10-05 |
| Terms last updated | 2025-06-19 | 2026-06-29 |
| Privacy policy last updated | 2026-06-08 | 2026-06-29 |
| Customer content may train models | yes | yes, with an opt-out |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 8.5k stars, 1.3M npm/wk, 433k PyPI/wk | 40k stars, 15.2M npm/wk |

## Verdicts

**GrowthBook.** GrowthBook Cloud's MCP server has four tools with read and write annotations, OAuth with dynamic client registration, and a 414-operation OpenAPI spec behind it. The free plan needs no card. The API tools pass paths and JSON bodies through without validation, every key is limited to 60 requests a minute, and audit logs are Enterprise only.

**PostHog.** PostHog suits agents that need to query product data and manage flags or experiments. Its hosted MCP server has OAuth scopes, a read-only mode and a one-tool CLI mode over 1,096 tools. The status page shows 31 incidents in 90 days, four on analytics queries, and three security incidents were disclosed in the last year.

## Before you call either

### GrowthBook

1. Connect to https://mcp.growthbook.io/mcp and complete OAuth in a browser. Use https://mcp.growthbook.io/mcp/api for the two API tools alone
2. Call `growthbook_list_skills` and `growthbook_read_skill` before writing. The API tools don't validate payloads, so use the paths the skill names
3. Stay under 60 requests a minute per key. On 429 wait for the `RateLimit-Reset` seconds before retrying
4. List calls return 10 items by default. Pass `limit` up to 100 and `offset` to page
5. A 422 is a soft warning. Resubmit with `?ignoreWarnings=true` only after reading the message

### PostHog

1. Add `?readonly=true` or the `x-posthog-read-only` header to the MCP URL unless the task needs writes
2. Pin the session with `x-posthog-project-id`, which also removes the `switch-project` and `switch-organization` tools
3. In CLI mode run `info <tool>` once before `call`, and send one `exec` command per request
4. On a 429 with code `api_queries_budget_exceeded`, wait for `Retry-After` and read `X-PostHog-Query-Budget-Remaining-Bytes`
5. Page SQL results by keyset on `timestamp`. `OFFSET` returns 400 for personal API keys, and results cap at 50,000 rows

## Questions

### Which is better for AI agents, GrowthBook or PostHog?

GrowthBook scores 70.1 (BB) on agent readiness against PostHog's 68.4 (B), and leads in 1 of 7 scored categories. PostHog leads on schema & documentation, security & auth and transparency & trust.

### Do GrowthBook and PostHog need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call GrowthBook and PostHog without installing anything?

Yes. GrowthBook has a hosted endpoint at https://mcp.growthbook.io/mcp and PostHog at https://us.posthog.com.

### Are GrowthBook and PostHog open source?

Yes. GrowthBook is open source (MIT for the core and for the MCP server. Three enterprise directories in the main repository are under GrowthBook's enterprise licence. GrowthBook Cloud is a hosted service under the Customer Agreement). PostHog is open source (MIT for the repository outside the `ee` directory, which has its own licence. PostHog Cloud is a hosted service under PostHog's terms).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/growthbook-vs-posthog.json, and with the fewest tokens: https://www.anchorterminal.com/compare/growthbook-vs-posthog.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "growthbook", "b": "posthog"}`. From a terminal: `anchor compare growthbook posthog`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/growthbook.json and https://www.anchorterminal.com/api/v1/tools/posthog.json

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